Mask structure



Oct. 10, 1944. J. E. DUGGAN 2,359,976

MASK STRUCTURE Filed Sept. 8, 1942 2 Sheets-Sheet 1 FIGJ.

INVENTOR. JAMES EDWARD DUQGAN Oct. 10, J, EDUGGAN I 2,359,976

MASK STRUCTURE Filed Sept. 8, 1942 2 Sheets-Sheet 2 FIGA.

INVENTOR.

JAME S E DWARD DU GGAN MMIW ATTORNEYS Patented Oct. 10, 1944 UNITED STATES PATENT OFFICE MASK STRUCTURE James Edward Duggan, New Brighton, Pa. Application September 8, 1942, Serial No. 457,656

I (on. 204 297) Claims.

This invention relates generally to devices that are used during plating or painting operations to protect certain portions of articles from plating material or paint applied to one or more adjacent portions thereof, and refers more particularly to a mask structure for portions of the hub of an airplane propeller.

Heretofore it has been customary, in accordance with Government specifications, to plate the splined portion of the hub that receives the correspondingly splined portion of the motor driveshaft. However when this is done it is difficult to keep the plating material from passing onto and impairing the bevelled bearing surfaces of the hub, usually located at opposite ends of the splined portion mentioned. In fact, notwithstanding efforts in the past to prevent it, some of the plating material was deposited upon one or both bearing surfaces and had to be removed. This required very careful work and considerable time, hence was costly and delayed production.

Thus, one of the essential objects of the present invention is to provide a mask structure capable of protecting thoroughly both bearing surfaces mentioned from the plating material applied to the intermediate splined portion of the propeller hub.

Another object is to provide a mask structure that not only accomplishes the masking of the bearing surfaces but also includes means for plating the intermediate splined portion while said surfaces are masked.

Another object is to provide a mask structure that has the added feature of serving as a holder for the hub during the plating operation.

Another object is to provide a mask structure that may be easily applied to and removed from the hub without marring any part thereof.

Another object is to provide a mask structure that is sturdy, durable and capable of being subjected to repeated handling and use.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a vertical sectional View through a propeller hub;

Figure 2 is an elevational view of a device embodying my invention;

Figure 3 is an elevational View of the device with the lower anode, block and wing nut removed, with the upper anode in section and showing the insulating sleeves on the rod;

Figure 4 is a detail View of the lower anode;

Figure 5' is a detail view of the lower block;

Figure 6 is a phantom perspective view of the lower block; and

Figure '7 is a plan View of the upper block of the device.

In the present instance I have combined in one device (1) means adapted to work in conjunction with any approvedelectro plating apparatus to accomplish the desired plating of one or more portions of the hub; (2) means for protecting or masking one or more other portions of the hub'during the plating operation; and (3) means for supporting the hub during the plating operation.

The art of electro-plating is Well-known and although various. methods and apparatus may be employed it is recognized that the passage of an electric current through a solution containing metallic ionsielectrically charged atoms of a metal) involves the deposition of the'metal on the cathode (the negative electrode). The main factors that influence the nature of the deposit are; chemical composition and'temperature of th electrolyte or solution, current density, concentration and circulation of the electrolyte, and the nature of the metal receiving the deposit.

' Although I have'illustrated my devicein conjunction with an airplane propeller hub it will be readily apparent that such device may be applied to any tubular surface as desired.

Referring nowto the drawings, A is a propeller hub having a central opening ID for the drive shaft (not shown) of a motor or other source'of power for the propeller of an airplane, and B is a device embodying my invention.

"As shown, the walls of the opening ID are provided intermediate opposite sides of the hub with a splined portion ll adapted to be engaged by a correspondingly splined portion of the motor drive shaft, and are provided at opposite ends of said splined portion H with oppositely inclined or bevelled bearing surfaces !2 and i3, respectively.

' The device B has a supporting rod i l provided at one end with an eye 15 and provided at its other end with a threaded portion 16. Preferably this rod i4 constitutes the negative electrode or cathode and is suspended during theplating operation by the eye 15 from any suitablemeans such as an agitating arm (not shown) of suitable electro-plating apparatus. v

l! is a tube of insulating material such as rubber or rubber composition sleeved on the rod 14 adjacent the eye 'l5'and carrying an anode or positive electrode I8, I9 is an electric conductor connected to the anode l8, and 20 and 2|, respectively, are spacers on the rod I4 at opposite sides of said anode I 8 and covered by insulating material such as rubber or rubber composition.

Sleeved on the rod 14 at longitudinally spaced points thereof, preferably correspondingly in distance to the distance between the bearing surfaces l2 and I3 of the hub A, are relatively thick circular masking elements or blocks 22 and 23, respectively, of relatively hard rubber or rubber composition and having oppositely inclined or bevelled edges 24 and 25, respectively, for surface to surface engagement with the bearing surfaces l2 and I3 of the hub. Preferably the block 22 abuts the spacer 2| and is provided on the underside thereof with a spacer 26.

2! is a relatively long tube of insulating material such as rubber or rubber composition sleeved on the rod l4 between blocks 22 and 23 and carrying a substantially cylindrical anode 28 having at one end an electric contact arm 29 that extends through an opening 22a in the block 22 and engages a suitable socket 311 in the anode l8.

Preferably insulating material such as rubber or rubber composition covers the spacer 26 and engages the upper end of tube 21 while the lower end of said tube is substantially flush with the lower end of the anode 28 and abuts another spacer 3| which is preferably formed integral with the block 23. An adjusting nut 32 of the winged type is mounted on the threaded portion 16 of the rod and is engageable with the lower side of the block 23 to maintain the parts inassembled relation.

In the present instance, the upper block 22 is provided with suitable holes 35 for the electrodeposition bath or plating fluid, while the lower block 23 contains a metallic hub 36 that is in metal to metal contact with the rod l4 and is electrically connected to metal contacts 31, 38 and 39, respectively, at circumferentially spaced points of the bevelled edge 25 by means of radially extending electric conductors 40, 4| and 42, respectively.

In use, when it is desired to protect or mask the bearing surfaces 12 and 13 of the hub A while the intermediate splined portion H is being plated, the winged nut 32 and lowerblock 23 are first removed from the rod I4 50 that the anode 28 on the rod may be inserted into the opening H) in the hub until the bevelled edge 24 of the upper block 22 engages and masks the bearing surface l2 of the hub. The block 23 and nut 32 are then re-assembled on the rod so that the bevelled edge 25 of said block engages and masks the bearing surface 13 of the hub, whereupon the winged nut 32 is tightened to clamp the blocks 22 and 23 firmly against the bearing surfaces l2 and I3 of the hub. The device 13 with the hub A thereon is then moved as a unit to the V surfaces l2 and 13 will be entirely free of plat a ts ing material. The removal of the hub A from the device may be accomplished after the nut 32 and block 23 have been removed from the rod l4 following the plating operation mentioned.

What I claim as my invention is:

1. A device of the class described comprising an upright cathodic rod having means at its upper end by which it may be supported from a bus bar, opposed work clamping blocks of insulating material sleeved upon the rod at longitudinally spaced points thereof and having portions shaped for sealing engagement with spaced portions of the work, separate anode sections sleeved upon but insulated from the rod at points above and below the uppermost block, an electrical connection between said sections extending through the uppermost block, means housed within one of said blocks for establishing an electrical connection between the rod and work, the lowermost of said blocks being adjustable lengthwise of the rod relative to the uppermost block to clamp the work, and a combined adjusting and clamping element on the rod beneath and engageable with the lowermost block to adjust the same.

2. A device of the class described comprising an upright cathodic rod having means at its upper end by which it may be supported from a bus bar, opposed work clamping blocks of insulating material sleeved upon the rod at longitudinally spaced points thereof and having portions shaped for sealing engagement with spaced portions of the work, separate anode sections sleeved upon but insulated from the rod at points above and below the uppermost block, an electrical connection between said sections extending through the uppermost block, means carried by one of said blocks for establishing an electrical connection between the rod and work, and means carried by the rod beneath the lowermost of said blocks for adjusting said lowermost block relative to the uppermost block to clampthe work.

3. A device of the class described comprising an upright cathodic rod having means at its upper end by which it may be supported from a bus bar, opposed work clamping blocks of insulating material sleeved upon the rod at longitudinally spaced points thereof and having portions shaped for sealing engagement with spaced portions of the work, electrically connected anode sections sleeved upon but insulated from the rod at points above and below the uppermost block, means carried by one of said blocks for establishing an electrical connection between the rod and work, and means carried by the rod beneath the lowermost of said blocks for adjusting said lowermost block relative to the uppermost block to clamp the work.

4. A device of the class described comprising an upright cathodic rod having mean at its upper end by which it may be supported from a bus bar, an anode sleeved upon but insulated from the rod adjacent its upper end and having a downwardly opening socket, opposed work clamping blocks of insulating material sleeved upon the rod beneath the anode and having portions shaped for sealing engagement with spaced portions of the work, a separate anode sleeved upon but insulated from the rod at a point between said opposed blocks and having an endwise projection extending through the uppermost of said blocks and engaging the socket in the first mentioned anode whereby the two separate anodes on the rod are electrically connected, means carried by one of said blocks for establishing an electrical connection between the rod and work, and means carried by the rod beneath the lowermost of said blocks for adjusting the lowermost block relative to the uppermost block to clamp the work.

5. A device of the class described comprising an upright cathodic rod having means at its upper end by which it may be supported from a bus bar, an anode sleeved upon but insulated from the rod adjacent its upper end, opposed work clamping elements of insulating material sleeved upon the rod beneath the anode and having portions shaped for sealing engagement with spaced portions of the work, a second anode sleeved upon but insulated from the rod at a point between said opposed elements and having a projection extending through the uppermost of said opposed elements and having an electrical contact with the first mentioned anode, means carried by one of said opposed elements for establishing an electrical connection between the rod and work, and means carried by the rod for holding the elements aforesaid against displacement from the rod and adjustable relative to the rod for moving the lowermost of said opposed elements relative to the uppermost of said elements to clamp the work.

JAMES EDWARD DUGGAN. 

